Is this a nutrient deficiency

Hi - first time grower here-

8 weeks into growing a white widow auto flower and the leaves have started to show some brown spots
Also noticed some of the leaf stems turning purple.

I am wondering if this is phosphorous or potassium deficiency -

She lives in a 2.5 x 2.5 gorilla tent
In a 3 gal pot of fox farm soil
I am using an HLG100 LED board - 18/6 cycle
I have used very little in the way of nutrients- the basic 3 general hydroponics flora micro, gro, and blooms - 1/4 strength in a gallon about a week ago - watered about 3/4 of the gallon
Another 3/4 of a gallon at 1/2 strength yesterday

Temps range 72 - 78
Humidity avg 40 %
The ph of the runoff using ph meter was 6.5
Today using the GH ph testing solution, it was around 5

Have a small fan running inside with the tent ports open

Any advice on what this is? Your help will be greatly appreciated



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Phosphorus deficiency


Yep could be the beginning of Phosphorus deficiency but also looks like some calcium deficiency starting as well.
I don’t use that nutrient line so I’m not sure what they have in them as far as calcium and Phosphorus. You may want to start upping your feed towards full strength.

Which Fox Farms soil?

Are you planning on flipping into flower soon?


Seems like a lack of bloom nutes in general, that plant is in full flowering mode and is too big for 1/4 dosage, needs the P and K, I’d give it a full dose of the week 7 flowering regimen. Could probably use some cal mag as well if you’re using ro or distilled water.


I agree Phosphorus deficiency. I keep these charts handy to help identify a deficiency.


Lol yes…yes they are…bloomin for sure…glazed right over the tops and focused on the leaves

Thanks everyone - per Hellraisers suggestion - will add a full regimen of GH 7 week cycle - will keep you posted

Thanks again


Buy a decent PH meter. Those test kits aren’t very accurate.

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Potassium deficiency?

In 4the week of flower.

If you are using happy frog soil this is the feeding schedule you really should be doing if you want great results!

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You can get this on Amazon for like 84 bucks! It’s called the Fox Farm dirty dozen. image|375x500

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